1. Field of the Invention
The present invention relates to a portable terminal. More particularly, the present invention relates to a method and a device for sensing rotation of a wheel in a portable terminal.
2. Description of the Related Art
In general, a “portable terminal” typically refers to an appliance for executing communication and data exchange while moving. Recently, various and useful functions have been implemented in portable terminals so as to be suited to the digital convergence era. For example, a user may use Audio On Demand (AOD) and Video On Demand (VOD) services, make a video call with a counterpart while watching a moving image of the face of the counterpart, or download and play a game. As the functions implemented in the portable terminals are diversified, a number of keys included in the portable terminals is gradually increased. With the increase of the number of keys in the portable terminals, the portable terminals gradually become larger, and users feel difficulty in using the terminals. In order to solve this problem, a portable terminal may be provided with a wheel, which allows a user of the portable terminal to easily control various functions of the portable terminal. Typically, a conventional wheel has two sensors, wherein the wheel is operated in such a way that an interrupt pattern of the two sensors caused by the rotation of the wheel is confirmed and the wheel is rotated in the direction corresponding to the interrupt pattern. However, the way to detect the rotation of the wheel through an interrupt pattern in this manner has a problem in that the swiftness and precision in sensing the movement of the wheel are poor. Therefore, what is needed is to enable the movement of such a wheel of a portable terminal to be swiftly and precisely detected so that the portable terminal can be more easily controlled.